In view of danf's quantitative analysis results published on this forum, I could not help but smile at this recent posting on eBay for a 7199 - based replacement board (IOW, the original). The bit that got me was the "not an unknown "new improved" circuit" part:
Extract Starts here:
This is an exact replacement for the original Dynaco PC-3 board, fabricated from 0.062" FR4 material with plated-through holes with pads and solder mask on both sides pre-assembled with a complete set of audiophile grade components using silver-bearing solder. If you are serious about getting the absolute best sound from your Dynaco Stereo 70, either this board or our board kit is a must. It uses the 7199 circuit from the original, not an unknown "new improved" circuit. Its mounting holes and numbering are identical to the original Dynaco PC-3, allowing easy replacement. It is easy to install using the included installation instructions.
All the components on this board are of the highest quality brought to you at a reasonable price. I had to shop several vendors to find the quietest resistors at the best prices. All components have been carefully chosen to support the high voltages found on the ST-70 board.....
Blah blah blah
...End of Extract